There seems to be no way to submit highscores in this version. I encourage everyone to get the downloadable version at http://www.metanetsoftware.com/ so you can compete in the highscore list.
I think it would make more sense if you didn't have 3 achievements for the same thing, such as scavenger/expert scavenger/master scavenger, and instead just made one achievement with multiple "levels", possibly more than 3. It would help make the achievement list less cluttered.
Also, for someone just starting the first level, it might be confusing that the upgraded cannons do "more damage", since the tier 1 cannons instantly kill any attackers anyway.
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